Review: Source Audio Hot Hand USB

Have you ever wanted to control your music just by wiggling your finger in the air? Source Audio makes products that translate physical movement into data that can wirelessly control music hardware and software in real time.

By Geary Yelton, Jul 1, 2014

Control MIDI software with a wave of your hand

Fig. 1. Hot Hand USB’s wireless transmitter contains an accelerometer that tracks your hand movements, and its receiver connects to your computer. Have you ever wanted to control your music just by wiggling your finger in the air? Source Audio makes products that translate physical movement into data that can wirelessly control music hardware and software in real time. Hot Hand USB addresses as many as ten simultaneous MIDI parameters on your computer by sensing the position of your hand in space. The system tracks movement along three axes (x, y, and z) as you rotate your hand or move your fingers up and down, resulting in MIDI Control Change (CC), Pitch Bend, or Aftertouch data.

Hot Hand USB has three components: a transmitter, a receiver, and software. The transmitter is a tiny box with a rubber strap that you wear as a ring on your finger. Its internal battery lasts about six hours and takes an hour-and-a-half to recharge using the included 5V charger. The receiver looks exactly like a flash drive and plugs into one of your computer’s USB ports (see Figure 1). The editing software monitors the ring’s output and routes it to whichever MIDI parameters you want to control (see Figure 2). The system can operate at a range of up to 100 feet.

Fig. 2. Hot Hand USB’s software component lets you map your hand movements to specific MIDI messages. Maps to the Stars After you download, install, and run the Hot Hand USB editor (Mac/Win), the software displays settings in a flowchart, from left to right. On the left are three “modules” that monitor the three axes, visually indicating changes in the ring’s position. To their right are six Processor modules; you can assign an axis to each, specify the axis’s range of motion, determine its center position, smooth its output to make changes less sudden, and make other adjustments.

Following the Processor modules are ten MIDI Output modules that convert processor data to MIDI data. This is where you determine the type of MIDI data that each processor will control. For each module, you can also specify MIDI channel, minimum and maximum values, and so on. In addition, the receiver responds to MIDI commands from your computer—MIDI Program Changes to change presets and Control Changes to turn MIDI Output modules on and off—which means you can automate Hot Hand USB’s behavior in your sequencer tracks.

Only A Motion Away Because the receiver is class-compliant, my computer recognized it as a MIDI device the moment I plugged it in, and Mac OS X’s Audio MIDI Setup automatically added it without having to manually insert a new device. I immediately gained control of tracks in Logic Pro and Pro Tools, and pairing Hot Hand USB with Ableton Live was a simple matter of enabling it in MIDI Sync preferences. For software that supports MIDI Learn, including most soft synths, pairing an axis with a MIDI parameter is especially easy.

Learning to precisely control pitch bend or LFO rate with the Hot Hand USB takes considerable practice (ever tried to play a theremin?), but it helps to specify a narrow range of values. It’s much easier to control volume, pan, filter cutoff, and modulation depth, or any parameter that simply turns on and off, but juggling multiple parameters can still be challenging.

Some may dismiss Hot Hand USB as a gimmick. But once you’ve mastered it, it’s a gimmick that looks pretty darn cool onstage while giving you unprecedented control over your sounds.